<div id="extjstree" style="overflow:auto; height:300px;width:250px;border:1px solid #c3daf9;"></div>

<script type="text/javascript">

	Ext.onReady(function(){
	    // shorthand
	    var Tree = Ext.tree;

	    var tree = new Tree.TreePanel({
	        el:'extjstree',
	        autoScroll:true,
	        animate:true,
	        enableDD:true,
	        containerScroll: true,
	        loader: new Tree.TreeLoader({
	            dataUrl:'<?php echo WSB_ADMIN_URL ?>test/extjs/json-tree/'
	        })
	    });

	    // set the root node
	    var root = new Tree.AsyncTreeNode({
	        text: 'ROOT',
	        draggable:false,
	        id: 0
	    });
	    tree.setRootNode(root);

	    // render the tree
	    tree.render();
	    root.expand();
	});

</script>